HEPiX Shells Scripts - Introduction


Here is an introduction to the HEPiX shells scripts.


Introduction

The main access to the UNIX operating system operating system is given by the UNIX shell. Any improvement to its usage can result in considerably more effective use of the system.

The alternatives

There are at least two major flavours, the Bourne shell and the C shell flavour.

Initially the Bourne shell (sh) was developed which provides nearly no comfort to the interactive user. A shell that is better than the Bourne shell for interactive use is the C shell but the good control of input and output as in sh went away. The shell script language was redesigned to resemble the C language. The tcsh as extension to csh has many extra features like command line editing and completion mechanisms.

David Korn from AT&T developed the Korn shell (ksh) and added also many features that made the C shell good for interactive work. The Korn shell became part of System V and even if it is on some systems it had one major problem: it isn't for free.

The Bash shell (Bourne again shell) from the GNU project is a free shell. Like the ksh, bash was based on the Bourne shell language and has many features from the C shell and from other operating systems.

The zsh written by Paul Falstad is also a Bourne-like free shell and like the tcsh has many additional features.

Summary

You can refer to document 162 "Shell comparison" from the CERN UCO to take advantage of a compilations of studies about the shell comparisons.

User perspective

The user wants a guaranteed functionality so that on all platforms the same feature works in the same way. Especially for inexperienced users a standardized look and feel is very important. Having a set of variables that describe the system the user can test these variables in his own scripts and becomes independent from some system dependencies.

System administrator view

He wants host-independent scripts which he can install on all systems with a minimal amount of modifications or configuration. The number of files to maintain should be kept as small as possible. In the scheme of standardized scripts the system administrator must have the chance to make local adaptations corresponding to individual needs.


HEPiX Shells Features and Results

What the HEPiX shells scripts provide

Moreover

Eventually

They are customised for each of the following platforms: AIX, HP-UX, OSF/1, Solaris, IRIX, SunOS, ULTRIX, ConvexOS, Linux and virtually any platform which follows the main UNIX streams can be adapted easily.

They are working with distributed file systems (NFS, AFS, probably with DFS as well).


Arnaud Taddei, 28-Jun-1996